Tying Off a Weather Balloon

To successfully tie off a Weather Balloon, you will need:

  • A fully inflated weather balloon, see our inflating a weather balloon page: Click Here
  • A handful of zip ties to close the balloon off and hold your payload train to the balloon securely.
  • A sharp and short scissors to cleanly cut the end of the zip ties off.
  • Our 15ft shock cord, with the bigger end that connects to the top of the parachute.
  • Helpers to help with tying the balloon off. It’s incredibly challenging to do this alone, even for the experienced.
Step 1 – Carefully remove the balloon neck from the inflation nozzle. Grip the balloon neck/inflator nozzle with both hands, making sure you have a good grip and that no helium will leak. Then have someone carefully pull down on the electrical tape pull-tab you created before inflating your weather balloon. The inflator nozzle will now slide easily out of the balloon neck.
Step 2 – Have a helper grip the balloon neck. Have them securely grip the balloon’s neck between their thumb and forefinger with their thumb and forefinger facing down. By facing down, your helpers’ extra fingers keep clear of most of the balloon neck where you will be doing all the work.
Step 3 – Place a zip tie around the neck of the balloon. Now you will want to take a zip tie and place it around the neck of the balloon where the inflator just was, tightening it as much as possible.
Step 4 – Place a second zip tie around the neck of the balloon. This step adds a double layer of redundancy to ensure no helium leaks out of the balloon neck. Now cut the end of each zip tie off and be very careful when using scissors not to poke into the balloon. I typically place my hand behind it, so it will not catch the balloon if I slip.
Step 5 – Place your spectra shock cord over the neck of the balloon. Fold the neck in half and have your helper clamp the end of the neck under his thumb and forefinger.
Step 6 – Place your spectra shock cord over the neck of the balloon. Fold the neck in half and have your helper clamp the end of the neck under his thumb and forefinger.
Step 7 – Wrap the balloon neck in electrical tape. This electrical tape secures everything in place and gives you peace of mind that you are not just relying on zip ties to keep everything together. The tape also prevents the zip ties from poking into the side of the balloon.